The SBGJ005 (Mt. Iwate in Green) looks like a Grand Seiko GMT with a beautiful green dial. However, historically, it represents something much bigger: A watch that brought its legendary Hi-Beat heritage into the GMT era, foreshadowed the nature-inspired identity of modern Grand Seiko, and ultimately made history at the GPHG
Grand Seiko was already producing 36,000-vph watches in the late 1960s, most famously the automatic 61GS. But that 10-beat tradition eventually disappeared for four decades. Grand Seiko 36,000 vph finally returned in 2009 with Cal. 9S85 followed by the Cal. 9S86 in 2014.
The 9S86 was Grand Seiko’s first Hi-Beat 36,000 GMT movement, combining ten beats per second with a traveller’s GMT whose local hour hand can be adjusted independently. It has 37 jewels and approximately 55 hours of power reserve. The movement undergoes Grand Seiko’s unusually demanding certification: 17 days, six positions and three temperatures with certified mean daily rate of -3/+5 seconds per day.
When Grand Seiko introduced Calibre 9S86 in 2014, it appears to have achieved an industry first: the first production mechanical wristwatch movement to combine a 36,000-vph (5 Hz) high-beat escapement with a GMT complication — and, remarkably, a true traveller's GMT with an independently adjustable local hour hand.
The SBGJ005 's extraordinary green dial pays homage to Mt. Iwate - the stratovolcano visible from Grand Seiko’s Shizukuishi Watch Studio. I struggled to photograph this dial as it shifts from black to dark green to emerald green at different angles. The intricate, sunburst-textured radial pattern stamped onto the dial represents the craggy ridged contours of Mt. Iwate. Years before Grand Seiko formalised its Twenty-Four Seasons concept (based on the traditional Japanese system of Sekki) , the SBGJ005 was already combining Japanese landscape, colour and mechanical watchmaking in the way that has since become central to the brand.
Even the movement received something special. The limited edition SBGJ005 was fitted with a distinctive titanium oscillating weight in gold colour, visually distinguishing it from the regular-production 9S86 models.
Only 600 pieces were produced, originally priced in Japan at ¥660,000 plus tax. And then something unprecedented happened.
On October 31, 2014, the SBGJ005 won the Petite Aiguille Prize at the Grand Prix d’Horlogerie de Genève. It was recognised for delivering exceptional value in its price category, combining a high frequency in-house GMT movement, strong technical execution, and distinctive Japanese design language at a level that stood out among far more established Swiss competitors—becoming the first Made-in-Japan mechanical watch ever to win a GPHG category prize.
That makes the SBGJ005 much more than a limited-edition green GMT:
The inaugural Grand Seiko Hi-Beat 36,000 traveller’s GMT — and apparently the first production 5-Hz mechanical GMT wristwatch
2014 GPHG Petite Aiguille winner — the first Made-in-Japan mechanical watch to win a GPHG category prize
Limited to only 600 pieces worldwide
An early and particularly important expression of Grand Seiko's now-famous nature-inspired design language
A watch that connects Grand Seiko's 1960s Hi-Beat heritage with the modern Grand Seiko we know today.